Improvement in propellers for vessels



2 Sh8BtS--Sh8et1. L. W. LANGDON.

Improvement in Propellers for Vessels.

Patented July I6, 1872.

\\\\s s s e s FW-VWQ 14H. HIOTU-UTHUGWAPKIC 2 Sheets--Sheet 2. L. W.LANGDON.

lmprovement in Propellers for Vessels.

No. 129,571. Patented July 16, 1872.

FIG, 5 FIG,6

- ing-rods on a line with their centers.

ITNITED STATES PATENT Orrrcn.

LEANDER W. LAN GDON OF NORTHAMPTON, MASSACHUSETTS.

IMPROVEMENT IN PROPELLERS FOR VESSELS.

Specification forming part of Letters Patent No. 129,571: dated July 16,187 2;

To all whom it may concern:

Be it known that I, LEANDER W. LANGDON, of Northampton, in the county ofHampshire and State of Massachusetts, have invented a new and usefulImprovement in Steam-Propellers; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawing making a part of thisspecification, and to the letters of reference marked thereon, in which-Figure 1 is a plan view of my invention, showing the upper cranks andtheir connect- Fig. 2 is a plan view, showing the position of thepropeller and its cranks when the upper cranks and their connecting-rodsare in the position shown in Fig. 1. Fig. 3 is a plan view, showing theupper cranks and their connecting rods as off their line of centers.Fig. 4 is a plan view, showing the position of the propeller and itscranks when the upper cranks and their connecting-rods are in theposition shown in Fig. 3. Fig. 5 is an end view of my invention asapplied to a boat, and Fig. 6 is a side view of the same.

Nature of the Invention.

The nature of my invention relates to the mode of propellingsteam-vessels by a propelling-blade arranged at the stern; and itconsists of two shafts placed in a vertical direction at the stern ofthe vessel, having at their upper ends a crank attached, to each ofwhich cranks is secured one end of a rod, and the other end of each rodis attached to a vibrating lever, which is pivoted to a point midwaybetween the two cranks- To the lower end of each shaft is attached theend of a blade, and all the cranks are attached to the shafts in thesame position relative to each other and to the shafts, and when poweris applied to the cranks at the upper ends of the shafts both the upperand lower cranks are so connected with each other by the connecting-rodsand by the propelling-blade that the shafts are caused to turn inopposite directions, and the propelling-blade, attached to and moved bythe lower cranks, is caused to make a movement in the water similar inits path to the form of the figure or numeral 8 when placed in ahorizontal position, the propelling-blade,

which stands in a vertical position, moving endwise transversely withreference to the length of the vessel, and also moving alternately, oneend and then the other, back from the vessel and against the water, andthus operating to propel the vessel with little disturbance of the wateras compared with the ordinary screw used; and to accomplish this motionof the propelling-blade is the object of my invention.

That others skilled in the art may be able to make and use my invention,I will proceed to describe the same.

In the drawing, B represents the stern of a vessel,havingthe shaftsceextendin g down in a vertical direction, and having a bearing in thepieces E and m, which are secured properly to the vessel, or in othersuitable pieces provided for that purpose, and having attached at theupper end of each the piece c,with the crankpin e therein, by means ofwhich a rotary motion may be given to each shaft. A rod, a, is connectedat one end to the crank-pin e, and at the other end to the vibratinglever f, which is pivoted at d midway between the shafts c. To the lowerend of each shaft 0 is attached a crank-piece, F, and to the end of eachsaid crank-piece F is attached the plate I, which is kept in itsvertical position and pivoted to the said crank-pieces by the rods h orother equivalent and suitable means.

The operation of my invention is as follows: If a. piston-rod, placedlengthwise the vessel, be connected to one of the upper crankpieces e torotate its shaft 0, the other crank and shaft 0 will also be caused torotate by means of the connecting-rods a, and lever f, but the twoshafts with their cranks will be rotated in opposite directions.

It will be seen, by reference to Fig. 1, that when the cranks c andconnection-rods a are in a line or on their centers, the lower cranks Fand the blade 'I are not in a line and are off their centers, and viceversa, so that as power is applied to rotate the shafts ethe lower setof cranks F assists the upper set a over the dead-point, and vice versa,and there is, consequently, no dead-point to overcome in its practicaloperation with power applied as above mentioned. As the shafts 0 arethus rotated the blade I is carried endwise by the cranks F rotating inopposite directions alternately from one side of the stern of the vesselto the other, and each time it is so moved the end of the blade whichprojects furthest to one side of the keel is also forced backward fromthe vessel and against the water, operating to push the vessel forward;and the whole force of this backward -movement of the blade is exertedin a direct line with the length of the vessel, and a great gain ofmotive force is the result. If the rotary motion of the shafts c bereversed, the force of the blade I is exerted against the water in theopposite direction, and the vessel is caused to move backward.

For practical operation the upper crank 0 might be made at any pointupon the shaft 0, as is common in the ordinary crank-shaft, or it mightbe made at the upper end of the shaft, according to the location of theengine.

Should the rudder of a vessel provided with a propeller of thisdescription become broken or disabled, the vessel might easily besteered by occasionally stopping the engines with the blade in theposition shown in Fig. 2, or in Fig. 4:, or in any other position whichwould give the vessel the proper course, and the blade would in thatcase perform the functions of a rudder for the time being, as thedifferent positions of the blade, when thrown more to one side of thekeel than the other, tend to impede the speed of the vessel or to giveit steerage upon the side to which it may be moved.

It is obvious that the shafts a may be connected and..be made to revolvein opposite directions by means of other devices equivalent to thatwhich I have described and shown;.

said upper cranks are coupled substantially as described, whereby theshafts are made to revolve in opposite directions, and thepropellingblade is thereby. operated in manner substantially as setforth.

L. W. LANGDON. Witnesses:

T. G. CoNNoLLY, CHAS. H. FOWLER.

